1. Field of the Invention
This invention is generally directed to the removal of a weld bead from the outside surface of a tube by means of scarfing and, more specifically, to an apparatus for removing a weld bead from a tube being produced by a continuous method.
2. Description of the Prior Art
Various methods and apparatus are known for removing weld beads from tubes. For example, U.S. Pat. No. 1,973,877 describes an apparatus using a pair of rotary shears which cooperatively removes the weld bead from a tube as the tube passes in a scarfing contact with the shears. One disadvantage of this apparatus is in the use of two shears which wear out unevenly and have to be replaced quite often.
Another form of removing a weld bead is described in U.S. Pat. No. 3,755,884 which uses a stationary scarfing tool which is positioned in a scarfing contact with a moving tube as it is being formed on a tube-forming machine. Since the scarfing tool removes the weld bead by a brute force, the formed tube is subject to deformation. Furthermore, the scarfing tool wears out fairly rapidly and requires frequent replacement.
A better apparatus for removing weld beads is described in U.S. Pat. No. 1,954,511, wherein in the embodiment shown in FIGS. 5 and 6, a ring-shaped cutter, rotatably mounted, removes the weld bead from a tube as it passes through the center of the cutter. The main objection to this type of cutter is that, should the cutter perform improperly and have to be removed, it is necessary to shut down the tube-forming apparatus so that the ring cutter can be replaced.